Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
2507 Lathing and Plastering — 2025 California Building Code
California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-09-25 · California
CBSC: official editions, supplements and errata
Italicized text is a California amendment to the model code, as printed in the official publication.
Cite as: 2025 California Building Code (Title 24, Part 2) § 2507 · Effective January 1, 2026 · Official source: Building Standards Commission
2507.1 General.¶
Lathing and plastering materials and accessories shall be marked by the manufacturer’s designation to indicate compliance with the appropriate standards referenced in this section and stored in such a manner to protect them from the weather.
2507.2 Standards.¶
Lathing and plastering materials shall conform to the standards listed in Table 2507.2 and Chapter 35 and, where required for fire protection, shall conform to the provisions of Chapter 7.
TABLE 2507.2—LATH, PLASTERING MATERIALS AND ACCESSORIES
| MATERIAL | STANDARD |
|---|---|
| Accessories for gypsum veneer base | ASTM C1047 |
| Blended cement | ASTM C595 |
| Cold-formed steel studs and track, structural | AISI S240 |
| Cold-formed steel studs and track, nonstructural | AISI S220 |
| Exterior plaster bonding compounds | ASTM C932 |
| Hydraulic cement | ASTM C1157; C1600 |
| Gypsum casting and molding plaster | ASTM C59 |
| Gypsum Keene’s cement | ASTM C61 |
| Gypsum plaster | ASTM C28 |
| Gypsum veneer plaster | ASTM C587 |
| Interior bonding compounds, gypsum | ASTM C631 |
| Lime plasters | ASTM C5; C206 |
| Masonry cement | ASTM C91 |
| Metal lath | ASTM C847 |
| Plaster aggregates Sand Perlite Vermiculite |
ASTM C35; C897 ASTM C35 ASTM C35 |
| Plastic cement | ASTM C1328 |
| Portland cement | ASTM C150 |
| Steel screws | ASTM C1002; C954 |
| Welded wire lath | ASTM C933 |
| Woven wire plaster base | ASTM C1032 |
GYPSUM PANEL PRODUCTS AND PLASTER
2507.3 Lath attachment to horizontal wood supports.¶
2507.3 Lath attachment to horizontal wood supports. [DSA-SS & DSA-SS/CC and OSHPD 1, 1R, 2, 4 & 5] Where interior or exterior lath is attached to horizontal wood supports, either of the following attachments shall be used in addition to the methods of attachment described in referenced standards listed in Table 2507.2.
1. Secure lath to alternate supports with ties consisting of a double strand of No. 18 W & M gage galvanized annealed wire at one edge of each sheet of lath. Wire ties shall be installed not less than 3 inches (76 mm) back from the edge of each sheet and shall be looped around stripping, or attached to an 8d common wire nail driven into each side of the joist 2 inches (51 mm) above the bottom of the joist or to each end of a 16d common wire nail driven horizontally through the joist 2 inches (51 mm) above the bottom of the joist and the ends of the wire secured together with three twists of the wire. 2. Secure lath to each support with 1/2-inch-wide (12.7 mm), 1 1/2-inch-long (38mm) No. 9 W & M gage, ring shank, hook staple placed around a 10d common nail laid flat under the surface of the lath not more than 3 inches (76 mm) from edge of each sheet. Such staples may be placed over ribs of 3/8-inch (9.5 mm) rib lath or over back wire of welded wire fabric or other approved lath, omitting the 10d nails. A minimum No. 8 wood screw in accordance with ANSI B18.6.1 with 1-inch minimum penetration into a wood joist shall be permitted to be used in lieu of the staples if they are installed with a 1-inch diameter washer.
Get a plain-English answer with a citation back to this text.
Ask AI about this code